*7.1.1 Antimicrobial compounds to eradicate biofilms: Substrates with antibiofilm activity*

In recent approaches many antimicrobial substances are screened with variable results on their ability to eradicate biofilms [38]. Before the discovery of antibiotics, silver (Ag) was used for decades as an anti-bacterial agent for food and water preservation [39]. After its ionization from Ag to Ag<sup>+</sup> , silver ions are capable of irreversibly denaturing key enzymes and in the process successfully killing mature biofilms after 24 hours of treatment [39, 40] as well as biofilms grown after 4–6 days though higher concentrations are needed. Biofilms that have been successfully eradicated by silver oxynitrate include *E. coli*, *S. aureus,* and *P. aeruginosa* biofilms [40].
